Heater block



FIG. 1 is a top view of a heater block of the present invention;

FIG. 2 is a side view thereof;

FIG. 3 is a bottom view thereof; and,

FIG. 4 a cross-section view thereof taken along line 4-4 in FIG. 1; and,

FIG. 5 is an enlarged view of the section labeled FIG. 5 in FIG. 4. 

CLAIM The ornamental design for a heater block, as shown and described. 